Zeroing adjustment for depth control system

ABSTRACT

A zeroing adjustment for a depth control system of an agricultural seed planting implement has an adjustable link to compensate for the variable effects of tolerance stack-up and wear, so that all planting units of the implement can be adjusted to a common zero ground penetration setting from which depth settings can be made.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a non-provisional divisional patent application based upon andhaving priority from U.S. non-provisional patent application Ser. No.14/295,993, entitled “ZEROING ADJUSTMENT FOR DEPTH CONTROL SYSTEM,”filed Jun. 4, 2014, with is hereby incorporated by reference herein inits entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to agricultural seed plantingimplements and to the depth-setting mechanism on furrow openingassemblies of such implements, and more particularly to an assembly foradjusting the depth-setting mechanism.

2. Description of the Related Art

Farmers utilize a wide variety of seed planting implements, includingseed drills and planters. In a known type of planting implement, seedplanting or row units are attached to a toolbar extending transverse tothe direction of planting. The toolbar is coupled to a tractor or otherwork vehicle suitable for pulling the planting implement along a fieldthat is to be seeded to a crop. Each planting unit includes a groundpenetrating assembly, often including one or more discs, for opening aseed trench or furrow in the ground as the planting implement is pulledacross a field. Components of the ground penetrating assembly shape thebottom and sides of the seed trench, and a seed metering device providesindividual seeds at a controlled rate for deposit in the seed trench.Furrow closing components of each row unit close the seed trench in acontrolled manner.

It is a desirable and perhaps even primary agronomic principle thatseeds should be planted at precisely controlled and consistent depthsboth within a row and from row to row. Since a single planting implementmay be used to plant several different types of crops and/or the samecrop in different planting locations under different planting andgrowing conditions, it is necessary that the planting depth isadjustable so that the seeds are placed at a depth that has beendetermined to be the best for seed germination and plant growth of theparticular crop under the existing and anticipated conditions.

To control planting depth, it is known to provide gauge wheels thattravel on the surface of the field to control the depth to which theground penetrating assembly can run, the positions of the gauge wheelsbeing adjustable so that the depth of the seed trench can be controlledwithin fractions of an inch. Adjustment linkages are provided forchanging the relative positioning of the gauge wheels with respect tothe ground penetrating assembly. It is known to move the adjustmentlinkage by a handle connected thereto, the handle engaging a registerhaving multiple positions for securing the handle to maintain theposition to which the handle is adjusted.

As growers have gained greater understanding about seed germination andplant growth, and as soil preparation procedures have changed andimproved, crop growers have demanded more precise control over seedplacement both in the spacing between seeds and in the depth at whichthe seeds are placed below the soil surface. Accordingly, there is botha demand and a need for even more precise control over the depth of theseed trench that is formed during planting operations. Whiledepth-setting mechanisms have been designed for ever more precisesettings, the linkages and other structures forming the depth settingmechanisms have multiple components and connections which can lead tosetting errors due to the variable effects of tolerance stack-up, wearand the like. In planting implements having multiple seed planting orrow units, it is necessary that all units be similarly calibrated sothat all units plant to the same planting depths when set to the samesettings. The multiple components and linkages present in depth-settingmechanisms can acquire unacceptably large variations from one row unitto another in the accumulated stack of tolerances in the component partseven when new, and after wear has occurred and/or if parts have beenreplaced, planting depths can vary significantly between row units thathave been adjusted to the same planting depth settings.

What is needed in the art is a structure for zeroing the depth settingmechanisms in a seed planting implement to adjust out the varyingeffects of tolerance stack-up and wear between different seed plantingunits of the implement.

SUMMARY OF THE INVENTION

The present invention provides a seed planting implement with consistentdepth setting control for ground penetrating components of the implementby providing an adjustable link in the adjustment mechanism tocompensate for the variable effects of tolerance stack-up and wear.

In one form thereof, the invention is directed to an agricultural seedplanting implement with a ground penetrating assembly, a depth settinglinkage assembly including a control assembly and a depth controllinkage arm associated with the ground penetrating assembly and havingadjustable positions for changing a depth to which the groundpenetrating assembly can operate. The depth control linkage arm isselectively variable in length.

In another form, the invention is an agricultural seed plantingimplement with a toolbar and a plurality of individual seed plantingunits connected to the toolbar. Each seed planting unit of the pluralityof seed planting units includes a ground penetrating assembly and adepth control assembly for changing a depth to which the groundpenetrating assembly can operate. Each depth control assembly isadjustable to a common setting from which depth settings are made forthe ground penetrating assemblies.

In a further form thereof, the invention is an agricultural seedplanting implement with a ground penetrating assembly, an adjustablegauge wheel supporting said ground penetrating assembly at controlledpenetration depths; and a depth control linkage arm adjustablypositioning said gauge wheel, said depth control linkage arm having aselectively variable length.

An advantage of the zeroing adjustment for depth control systemsdisclosed herein is that the penetration depth for seed plantingequipment can be more accurately and consistently set across multipleplanting units of an agricultural seed planting implement.

Another advantage of the zeroing adjustment for depth control systemsdisclosed herein is that it compensates for the variable effects oftolerance stack-up and wear.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of an embodiment of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a perspective view of an agricultural seed planting implement;

FIG. 2 is a perspective view of one of the seed planting units of theseed planting implement;

FIG. 3 is a side view of the seed planting unit;

FIG. 4 is another perspective view of the seed planting unit, showingthe unit from an angle different from the angle shown in the perspectiveview of FIG. 2;

FIG. 5 is a fragmentary side view of the seed planting unit illustratinginner components used for depth setting;

FIG. 6 is a perspective view a depth setting linkage assembly in theseed planting unit;

FIG. 7 is a side view of the depth linkage assembly;

FIG. 8 is a fragmentary elevation view of the seed planting unit;

FIG. 9 is a cross-sectional view of the seed planting unit; and

FIG. 10 is another perspective view of the linkage assembly as installedand adjusted.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplification set out hereinillustrates one embodiment of the invention and such exemplification isnot to be construed as limiting the scope of the invention in anymanner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings more specifically and to FIG. 1 inparticular, a seed planting implement 10 is shown. Seed plantingimplement 10 has a frame that includes a tow bar assembly 12 having atow bar 14 and a connection assembly 16 at the longitudinally forwardend thereof configured for mating with a corresponding hitch of atractor or other work vehicle (not shown) for pulling seed plantingimplement 10 through a field. A laterally extending toolbar 18 isgenerally transverse to tow bar 14 and thereby generally transverse tothe direction implement 10 is towed during planting operations. Aplurality of seed planting units (or row units) 20 are connected totoolbar 18 in a side by side relationship, each of the seed plantingunits (row units) being substantially identical to the others. In theexemplary embodiment shown, seed planting implement 10 includes sixteenseed planting units 20, only some of which are identified with referencenumbers; however, it should be understood that more or fewer seedplanting units can be provided on a particular seed planting implement.

Referring now primarily to FIG. 2 through FIG. 5, each seed plantingunit 20 includes a frame 22 that is connected to toolbar 18 by upperarms 24 and lower arms 26, each arm 24, 26 being connected to frame 22and to toolbar 18. Accordingly, each seed planting unit 20 extendsrearward from toolbar 18 to plant a row of seeds as seed plantingimplement 10 is towed across a field. The individual planting units 20are spaced along toolbar 18 to provide planted seed rows of a desiredspacing. During a planting operation, forward movement of seed plantingimplement 10 causes each seed planting unit 20 to form a seed trench,deposit equally spaced seeds in the seed trench and close the seedtrench over the seeds deposited in the seed trench.

Each seed planting unit 20 includes a ground penetrating or seed trenchopening assembly 30 (FIG. 3) having a pair of forwardly and downwardlyangled opening discs 32 that converge forwardly and downwardly to open afurrow or seed trench as seed planting implement 10 moves forward. Aseed metering system 34 receives seeds from a seed hopper 36 andprovides individual seeds at a controlled rate to a seed tube 38 fordeposit in the bottom of the seed trench formed. A vacuum system 40(FIG. 1), which includes a fan 42 and air lines 44, provides vacuum toseed metering system 34 for the operation of the seed metering system insupplying seeds to seed tube 38.

A seed trench closing mechanism 50 (FIG. 1) at the trailing end of eachseed planting unit 20 closes the seed trench after the seeds have beendeposited in the seed trench. Seed trench closing mechanism 50 includesa pair of closing wheels 52 (FIG. 2) that operate on opposite sides ofthe seed trench to move soil back into the seed trench and over theseeds deposited in the bottom of the seed trench. A trailing press wheel54 (FIG. 1) travels along the top of the seed trench and firms the soilreplaced in the seed trench to eliminate air pockets.

The depth to which opening discs 32 are allowed to penetrate the groundis controlled by a depth control assembly 60 (FIG. 5) that includes apair of gauge wheels 62, gauge wheel arms 64 and a depth setting andlinkage assembly 80. One of the gauge wheels 62 is provided adjacenteach opening disc 32. Each gauge wheel 62 is rotatably mounted on one ofthe gauge wheel arms 64 that are pivotally connected at a pivotalattachment 66 to seed planting unit frame 22. Each gauge wheel arm 64has a wheel retention segment 68 extending generally rearward frompivotal attachment 66 and a control segment 70 extending generallyupward from pivotal attachment 66. Pivotal movement of gauge wheel arm64 about pivotal attachment 66 to frame 22 changes the relative heightposition of gauge wheel 62.

A pivoted position to which each gauge wheel arm 64 is placed iscontrolled by depth setting and linkage assembly 80 having a depthsetting control assembly 82, a depth control linkage arm 84 and a wobblebracket 86 connected to linkage arm 84 by a pivotal connection 88.Control assembly 82 adjusts an axial position for linkage arm 84 andthereby the position of wobble bracket 86, with wobble bracket 86engaging control segments 70 of gauge wheel arms 64. Raising gaugewheels 62 allows opening discs 32 to penetrate deeper into the ground,and lowering gauge wheels 62 limits the depth to which discs 32 canpenetrate into the ground.

Referring now primarily to FIG. 4 through FIG. 6, control assembly 82includes a pivot arm 90 of general V-shape, with a pivotal connection 92at the base thereof to seed planting unit frame 22. An inner arm 94 ofpivot arm 90 has a pivotal connection 96 to depth control linkage arm84. An outer arm 98 of pivot arm 90 extends through a depth settingregister 100. Depth setting register 100 defines a slot 102 with a firstrow of notches 104 along one side of slot 102 and a second row ofnotches 106 along an opposite side of slot 102. Opposed pairs of notchesincluding one of the notches 104 and one of the notches 106 definesecuring locations for securing the position of pivot arm 90 afteradjustment thereof.

A handle 108 is provided on the distal end of outer arm 98 and includeslaterally projecting position holding pegs 110, 112 for engaging notches104, 106 of register 100. The pairs of notches including one of thenotches 104 and one of the notches 106 secure the position of pivot arm90 by receiving and engaging pegs 110, 112. Handle 108 is mounted on aspring 114, and can be depressed relative to outer arm 98 such that pegs110, 112 disengage notches 104, 106 by sliding inwardly through thenotches so that handle 108 can be moved fore and aft in slot 102 toalign pegs 110, 112 with different pairs of notches 104, 106. As handle108 rebounds outwardly, pegs 110, 112 slide into the pair of notches104, 106 with which the pegs are aligned. Movement of handle 108 foreand aft pivots pivot arm 90 about its pivotal connection 92, and therebyextends or withdraws depth control linkage arm 84, to alter the positionof wobble bracket 86, which in turn controls the positions of controlsegments 70 and thereby the allowable height of gauge wheels 62.

Depth control linkage arm 84 includes a rearward portion 130 that isconnected to pivot arm 90 by pivotal connection 96, and a forwardportion 132 that is connected to wobble bracket 86 by pivotal connection88. An intra-link connection 134 between rearward portion 130 andforward portion 132 is axially adjustably so that the overall length oflinkage arm 84 is selectively variable. Rearward portion 130 and forwardportion 132 are telescopically engaged with one another to accommodatethe overall axial adjustability of connection 134 to change the overalllength of linkage arm 84.

Referring now more particularly to FIG. 7, connection 134 includes abolt 136 extending through one or more fixed block 138, 140 fixedbetween side plates 142, 144 of forward portion 132 and received bythreaded engagement in a threaded block 146 affixed to rearward portion130. Bolt 136 includes a shank 150 that is threaded along at least aportion of an end thereof, and a head 152 having a drive configuration154 (FIGS. 9 & 10) formed therein for engagement by an appropriate toolfor rotating bolt 136. In the exemplary embodiment shown, driveconfiguration 154 is a hexagonal depression for receiving a hex key(Allen wrench) in rotational drive engagement. It should be understoodthat drive configuration 154 can be of other shaped depressions in head152 to engage other internally received drive tools, or driveconfiguration 154 can be an external shape of head 152 to receive awrench, drive socket or the like. Head 152 includes opposed externalflats 156, 158 (FIG. 10) that also can receive a wrench, drive socket orthe like. Advancing the threaded engagement of bolt 136 into threadedblock 146 decreases the overall length of depth control linkage arm 84,and retracting the threaded engagement of bolt 136 from threaded block146 increases the overall length of depth control linkage arm 84.

Referring now particularly to FIG. 10, a lock mechanism in the form of abracket or cage 160 is provided to secure the position to which bolt 138has been adjusted. Cage 160 has sides 162, 164 and an end 166. End 166has a shaped hole 168 therein including opposed flats 170, 172 toreceive and engage head 152, with flats 156, 158 of head 152 receivedagainst flats 170, 172 of shaped hole 168 to prevent further rotation ofbolt 138. Sides 162, 164 of cage 160 are received against side plates142, 144, and together side plates 142, 144 and sides 162, 164 formaligned holes 174, 176 for receiving a pin forming pivotal connection88. It should be understood that other structures can be used forpreventing the unintended rotation of bolt 136 after the adjustmentthereof.

Zero adjustment or calibration of depth control assembly 60 is performedupon initial assembly and can be performed again from time to time as amaintenance procedure. For example, it may be desirable to zero adjustthe system after significant wear and/or when replacement parts havebeen installed. Zero adjustment is performed with wobble bracket 86,pivotal connection 88 and cage 160 not yet installed (during initialassembly) or removed (when performed as a maintenance step). Seedplanting implement 10 is adjusted so that toolbar 18 is elevated,lifting all seed planting units 20 off the ground. As illustrated inFIG. 8, each gauge wheel 62 drops, pivoting its respective gauge wheelarm 64 about the pivotal attachment 66 thereof until adjustable controlsegment 70 contacts a frame stop 178. This allows removal of wobblebracket 86, pivotal connection 88 and cage 160 when performed as amaintenance operation or the insertion of depth control linkage arm 84during assembly.

With seed planting implement 10 thus prepared, toolbar 18 is lowereduntil opening discs 32 barely contact a flat level surface upon whichimplement 10 is positioned. Opening discs 32 thereby rest at a zeropenetration setting, and depth control assembly 60 can be adjusted forproper registration of handle 108 at the zero penetration setting.Control assembly 82 is adjusted such that handle 108 is engaged with theappropriate notches 104, 106 for a zero penetration setting. Bolt 136 isthen adjusted relative to threaded block 146 to advance further into orto withdraw further from threaded block 146, while at all timesremaining threadedly engaged there with. In this way, the overall lengthof depth control linkage arm 84 is adjusted so that when wobble bracket86 is re-attached thereto it will properly engage control segments 70 ofgauge wheel arms 64 and without unacceptable looseness. It should beunderstood that the appropriate length for control linkage arm 84 can bedetermined in numerous ways, including measurement between the endthereof and a fixed point such as, for example, depth setting register100 or another fixed point of reference. A convenient way fordetermining the proper overall length of linkage arm 84 is by the use ofa gauge 180. As illustrated in FIG. 9, gauge 180 includes wings 182, 184to be received in wobble bracket slots 186 of control segments 70. Bolt136 is rotated so as to advance further into, or withdraw further fromthreaded block 146 and thereby change the overall length of depthcontrol linkage arm 84 until the outer end of control linkage arm 84 isreceived at a designated position relative to gauge 180 and wings 182,184 are properly received in wobble bracket slots 186. Bolt head 152 isadjusted as necessary so that flats 156, 158 thereof are properlypositioned such that cage 160 can be installed with shaped hole 168thereof engaging bolt head 152, with flats 156, 158 of bolt head 152disposed against flats 170, 172 in shaped hole 168 of cage 160. Gauge180 is removed, and cage 160 is installed. Wobble bracket 86 and pivotalconnection 88 are installed, thereby securing cage 160 in position andlocking bolt 136 against unintended rotation.

When all row units 20 of seed planting implement 10 are adjusted in thismanner to a common zero penetration setting, each will have a commonelevation relative to the zero setting to which it was adjusted. Eachcan then be set so that the opening discs 32 thereof will penetrate asame depth into the ground if the control assemblies 82 thereof areadjusted to similar settings in registers 100. In that way, all rowunits that are set to the same settings will deposit seeds at the samedepths below the surface of the ground.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

What is claimed is:
 1. An agricultural seed planting implement,comprising: a toolbar; a plurality of individual seed planting unitsconnected to said toolbar; each seed planting unit of said plurality ofseed planting units including a ground penetrating assembly including anopening disc, and a depth control assembly for changing a depth to whichthe ground penetrating assembly can operate, each said depth controlassembly being individually adjustable to a common zero groundpenetration setting from which depth settings are made for said groundpenetrating assemblies, the depth control assembly including at leastone gauge wheel and one gauge wheel arm and a depth control linkageassembly including a depth control linkage arm associated with theground penetrating assembly, and having adjustable positions forchanging a depth to which the ground penetrating assembly can operate;and a movably adjustable control assembly which provides depthadjustment settings for the depth control linkage arm, wherein thecontrol assembly is configured to lock the depth control linkage arminto a selected position which prevents axial movement of the arm,wherein said depth control linkage arm is selectively variable inlength, and the depth control linkage arm comprises one end including afirst end portion which overlaps at least a portion of a second endportion for axial adjustment of the arm, such that the arm is adjustablypositioned in a selected length and the first end portion and the secondend portion are locked together into the selected length via a lockmechanism which adjustably couples the first end portion to the secondend portion, wherein the lock mechanism substantially prevents axialmovement of the one end of the arm.
 2. The agricultural seed plantingimplement of claim 1, wherein said axially adjustable connectionincludes a bolt connecting said first end portion and said second endportion.
 3. The agricultural seed planting implement of claim 2, whereinsaid bolt includes a head, and said lock mechanism engages said head inan adjusted position of said head.
 4. The agricultural seed plantingimplement of claim 1, wherein said depth control assembly includes aframe stop which interacts with said control segment in the zero groundpenetration setting.